I am intentional about my diet (Mediterranean) and don't find it super easy to get 1.6 - 2.0 g of protein per 1 kg of weight per day. I think the protein bars serve younger generations who are stretched to the max and don't have extra time to carefully shop -cook - workout - and attend to jobs, family and other social obligations. I think that needs to be acknowledged. Protein bars fill a gap. The bigger problem is lack of prepared high quality, affordable foods available at markets and restaurants for easy access.
I've never though increased protein would in and of itself lead to increased muscle mass. But if I'm eating 2000 calories a day, 45% carbohydrates, 40% fats, 15% protein, and I change that to 40% carbohydrates, 35% fats, 25% protein, I'd expect a different body composition eventually.
Very helpful analysis, as usual! I would be interested in your take on creatine supplements, which are promoted for burst strength (as in sports and weight training) and possible anti-aging benefits. What seems to be missing from most dietary advice is explicit recommendations to strictly limit intake of simple carbohydrates. For many of us, simple carbs seem addictive (one cookie is too many and a dozen isn't enough) whereas following a diet of low-glycemic-load foods seems very beneficial to comfortable and substantial weight loss without obvious ill effects, even when loads of fatty meats are a component. I have only personal and other anecdotal experience of these effects and no commercial interests in these matters; the only relevant study I know of is the "A-to-Z Study" which seems widely ignored (https://pubmed.ncbi.nlm.nih.gov/17341711/).
Great points on simple carbs. Not sure about creatine. The data supports helping muscle recovery after strength training but other potential benefits are unclear
Eric, a terrific post. Thank you from an MD PhD in Physiological Sciences. I note that ChatGPT 5 recommended a "sweet spot" for me (a 60 year old) at 1.6-1.8g/kg of body weight. And also wrote that going up to 2g is safe if my kidney function is fine. It seems clear to me that companies with vested interests are successfully biasing the information coming from OpenAI. Scary stuff given the hundreds of millions of people now using ChatGPT for "search". I'd love you to do a post on the topic of industry publishing methods (e.g. only publishing the results that favour their products) being used across much of the "longevity" industry.
You're absolutely right about the bias of LLMs that are based on promotional inputs from industry and influencers. Hard to get the data on it but would certainly be worthwhile to pursue this. Thanks!
This article is a great insight into our current obsession and trends with protein intake . Very high protein intake and counting macros is detrimental to the ground fact that we are starting to get deficient in micronutrients. These ultra processed proteins are not rich in micronutrients . Which help drive so many enzymatic functions of our bodies . Eating rich diverse food categories is utmost important while keeping within caloric limits. strength training is key for muscle growth.
Good question. Resistance training helps to reduce muscle loss but all the companies that make GLP-1 drugs are investing in muscle building drugs line myostatin. No data that I’ve seen on high protein.
I appreciate your effort to make sense of it all...and as recently as when you wrote your book, , the fad was leucine supplementation because studies showed that leucine levels decreased with age...except that further studies showed that leucine levels change randomly with age....the advice is constantly changing.
I also think that most advice is aimed at specific audiences...and I'm not in that audience.
As a single elderly person of normal weight, living alone, cooking for myself, I definitely was not getting adequate protein. I had to double my protein intake to get to 1g/kg/day. My goal is certainly not to "bulk up" . It's to feel active and interested. Maybe placebo effect, but I am much more active than I was on a lower protein diet.
Also, you need a lot less protein if you use animal protein, which matches your needs, than you do if you use vegetable protein, which causes you to waste 20-30% of the of amino acids that you take in, because they are present in excess if you are making animal protein (we are animals). All that extra nitrogen goes into urea to the kidneys. As you know, renal function tends to decrease steadily with age.
The reasons that we should not eat like cows or chickens are many. Among them:
Cows and chickens can make the essential amino acids we can't make.
Cows have huge grinding teeth and chew cud and break down cell walls of plant cells. Chickens eat pebbles and grind plants in a muscular stomach. Other herbivores have other methods (see rabbits). That releases the nutrition in those plant cells.
Humans don't have mechanisms to break down the cell walls. We can't get nutrients out of raw vegetable cells. We have to cook them, grind them, or put them in a blender. Raw salads are not nutritious. (Horrors)
I think that most of the explanations based on activity of mTor and AMPK are spurious. We really don't know how mTor /AMPK activity changes in the multiple conditions that each person experiences each day. Mice? They've lived in the labs for 100 years, and each strain lacks enzymes present in others. Breed strains to each other, and any of them will live longer (lots of studies).
Dr. Eric, be careful to modify your recommendations to serve the individual patient. Tell a scrawny elderly patient to actually calculate their protein intake. I recommend lean animal protein and lots of cooked vegetables. Maybe the average American gets too much protein, but the average over-80 person probably gets too little.
I wasn’t even aware of this craze, but nonetheless appreciated the intelligent, thorough way in which you debunked it. I am also highly impressed with your own exercise regimen. I recently started a new exercise regimen given to me by the formidable Marilyn Moffat (among many other accolades and achievements, she co-wrote a wonderful book called “Age-Defying Fitness.” https://www.peachtreebooks.com/author/marilyn-moffat/). Marilyn is in her early 80s, still teaching students and pushing those of us lucky enough to be her patients to demand more of ourselves so as to be as healthy as we can as long as we can. There is definitely a synergy with your excellent work here. Too few pay attention to what we really need to do as we age, which makes your work all the more important.🙏🙏🙏
im a sexagenarian(?) and ive increased protein after personal results from continuous glucose monitoring (cgm). basing, or at least beginning, a meal with proteins seems to buffer cgm spikes, and snacking on proteins (cheese, nuts, minimally sweetened chocolate) seems key to preventing the hyper/hypo glycemic swings. the same for vegetables, though that is not controversial.
this is not an attempt to increase dietary protein per se, but a shift in diet away from carbs towards these two categories, which has had a net overall effect of increased protein intake. this aspect was not mentioned in your article, so i thought id point out: some part of health gains reported for high protein diets are from the reduction of glycemic intake and esp. these initial spiking events.
I suspect the protein leverage hypothesis may hold some truth, that protein needs vary by age. As for Huberman and Attia, I agree the former often promotes rubbish. Attia, on the other hand, has a mind sharper than any razor and is no slouch with data, and given your past interaction with him, I'm surprised you would simply dismiss him by saying he declined questions from the NY Times. So what? His views on this topic are not at all hard to find, along with his usual cogent and logical interpretation of the data linked to in his article (see below). As an older woman whose digestion is not what it once was, who fears getting the same sarcopenia that doomed her mother, I lift weights AND take a protein supplement on those days. It's actually quite hard for me to get even the measly RDA without a supplement.
My question is how well have the mortality, atherosclerosis and Type2DM associations accounted for confounders such as LDL, obesity or body fat percentage, etc. It is, at least in theory, possible to eat a mostly plant-based diet, high in fiber and unsaturated fats and supplement with animal protein devoid of other nutrients. This could isolate the effects of higher caloric intake protein intake.
I usually don’t eat lunch. Just a snack. Sometimes I’ll have sliced nonfat turkey on a slice of bread (cut in half) with some arugula and Dijon mustard
Thank you so much for taking the time to respond! And thank you for all the work you do bringing science to us. It’s refreshing and unbelievably important right now especially. Thanks again.
Dr. Topol, thank you for your Ground Truths article on protein intake. Question: is there a benefit to taking a supplement based on a collagen hydrolysate on joints? Is there clinical trial data supporting this?
Thanks for giving attention to this issue. You’re right that protein dominates public discussion, and I share your skepticism of influencer-driven hype. I was an early fan of Huberman’s science-focused content, but agree he’s drifted from rigor. That said, broader interest in higher protein isn’t simply the product of influencer “brainwashing.”
From the lens of body composition—and especially sports performance—the case for higher protein is fairly strong. Consensus guidelines (ACSM, ISSN) recommend 1.2–2.0 g/kg/day for active individuals. In hypocaloric periods, higher intakes can aid lean mass retention, though with diminishing returns. The “1 g/lb” advice overshoots for most people: it’s not harmful with healthy kidneys, but rarely necessary outside of competitive or aesthetic goals. Two caveats: plant protein requires higher intake to achieve equivalent muscle protein synthesis (MPS), and older adults need more protein to trigger MPS due to anabolic resistance.
For an excellent review, see: https://www.strongerbyscience.com/protein-science/ The quoted 1.6 g/kg/day isn’t a hard ceiling but more of an inflection point; most people get ~90% of benefits there, but those pursuing maximal gains can justify going higher.
On safety, the balance of evidence shows high protein does not harm healthy kidneys. Recent studies even suggest mortality benefits of higher protein in CKD stages 1–3 (see recent large JAMA study and subsequent AJKD commentary calling for a more nuanced approach). At minimum, the science here is evolving—not closed.
As for CVD risk, here’s where I think we mostly agree: plant protein is clearly beneficial. Lean animal protein looks neutral, while processed and likely red meat drive risk. Mechanistic/animal studies on leucine are worth paying attention to, but shouldn’t be leveraged into broad anti-protein recommendations. The totality of evidence just doesn’t support that.
I am intentional about my diet (Mediterranean) and don't find it super easy to get 1.6 - 2.0 g of protein per 1 kg of weight per day. I think the protein bars serve younger generations who are stretched to the max and don't have extra time to carefully shop -cook - workout - and attend to jobs, family and other social obligations. I think that needs to be acknowledged. Protein bars fill a gap. The bigger problem is lack of prepared high quality, affordable foods available at markets and restaurants for easy access.
I've never though increased protein would in and of itself lead to increased muscle mass. But if I'm eating 2000 calories a day, 45% carbohydrates, 40% fats, 15% protein, and I change that to 40% carbohydrates, 35% fats, 25% protein, I'd expect a different body composition eventually.
Very helpful analysis, as usual! I would be interested in your take on creatine supplements, which are promoted for burst strength (as in sports and weight training) and possible anti-aging benefits. What seems to be missing from most dietary advice is explicit recommendations to strictly limit intake of simple carbohydrates. For many of us, simple carbs seem addictive (one cookie is too many and a dozen isn't enough) whereas following a diet of low-glycemic-load foods seems very beneficial to comfortable and substantial weight loss without obvious ill effects, even when loads of fatty meats are a component. I have only personal and other anecdotal experience of these effects and no commercial interests in these matters; the only relevant study I know of is the "A-to-Z Study" which seems widely ignored (https://pubmed.ncbi.nlm.nih.gov/17341711/).
Great points on simple carbs. Not sure about creatine. The data supports helping muscle recovery after strength training but other potential benefits are unclear
Eric, a terrific post. Thank you from an MD PhD in Physiological Sciences. I note that ChatGPT 5 recommended a "sweet spot" for me (a 60 year old) at 1.6-1.8g/kg of body weight. And also wrote that going up to 2g is safe if my kidney function is fine. It seems clear to me that companies with vested interests are successfully biasing the information coming from OpenAI. Scary stuff given the hundreds of millions of people now using ChatGPT for "search". I'd love you to do a post on the topic of industry publishing methods (e.g. only publishing the results that favour their products) being used across much of the "longevity" industry.
You're absolutely right about the bias of LLMs that are based on promotional inputs from industry and influencers. Hard to get the data on it but would certainly be worthwhile to pursue this. Thanks!
This article is a great insight into our current obsession and trends with protein intake . Very high protein intake and counting macros is detrimental to the ground fact that we are starting to get deficient in micronutrients. These ultra processed proteins are not rich in micronutrients . Which help drive so many enzymatic functions of our bodies . Eating rich diverse food categories is utmost important while keeping within caloric limits. strength training is key for muscle growth.
I’d be interested to know what the use of GLP-1 inhibitors would have on this guidance?
Good question. Resistance training helps to reduce muscle loss but all the companies that make GLP-1 drugs are investing in muscle building drugs line myostatin. No data that I’ve seen on high protein.
I appreciate your effort to make sense of it all...and as recently as when you wrote your book, , the fad was leucine supplementation because studies showed that leucine levels decreased with age...except that further studies showed that leucine levels change randomly with age....the advice is constantly changing.
I also think that most advice is aimed at specific audiences...and I'm not in that audience.
As a single elderly person of normal weight, living alone, cooking for myself, I definitely was not getting adequate protein. I had to double my protein intake to get to 1g/kg/day. My goal is certainly not to "bulk up" . It's to feel active and interested. Maybe placebo effect, but I am much more active than I was on a lower protein diet.
Also, you need a lot less protein if you use animal protein, which matches your needs, than you do if you use vegetable protein, which causes you to waste 20-30% of the of amino acids that you take in, because they are present in excess if you are making animal protein (we are animals). All that extra nitrogen goes into urea to the kidneys. As you know, renal function tends to decrease steadily with age.
The reasons that we should not eat like cows or chickens are many. Among them:
Cows and chickens can make the essential amino acids we can't make.
Cows have huge grinding teeth and chew cud and break down cell walls of plant cells. Chickens eat pebbles and grind plants in a muscular stomach. Other herbivores have other methods (see rabbits). That releases the nutrition in those plant cells.
Humans don't have mechanisms to break down the cell walls. We can't get nutrients out of raw vegetable cells. We have to cook them, grind them, or put them in a blender. Raw salads are not nutritious. (Horrors)
I think that most of the explanations based on activity of mTor and AMPK are spurious. We really don't know how mTor /AMPK activity changes in the multiple conditions that each person experiences each day. Mice? They've lived in the labs for 100 years, and each strain lacks enzymes present in others. Breed strains to each other, and any of them will live longer (lots of studies).
Dr. Eric, be careful to modify your recommendations to serve the individual patient. Tell a scrawny elderly patient to actually calculate their protein intake. I recommend lean animal protein and lots of cooked vegetables. Maybe the average American gets too much protein, but the average over-80 person probably gets too little.
I wasn’t even aware of this craze, but nonetheless appreciated the intelligent, thorough way in which you debunked it. I am also highly impressed with your own exercise regimen. I recently started a new exercise regimen given to me by the formidable Marilyn Moffat (among many other accolades and achievements, she co-wrote a wonderful book called “Age-Defying Fitness.” https://www.peachtreebooks.com/author/marilyn-moffat/). Marilyn is in her early 80s, still teaching students and pushing those of us lucky enough to be her patients to demand more of ourselves so as to be as healthy as we can as long as we can. There is definitely a synergy with your excellent work here. Too few pay attention to what we really need to do as we age, which makes your work all the more important.🙏🙏🙏
“ In the Table below, I culled together all the published meta-analyses …”
To cull is to eliminate. Were you looking for “pulled together “?
thanks, fixed
thanks for the article.
im a sexagenarian(?) and ive increased protein after personal results from continuous glucose monitoring (cgm). basing, or at least beginning, a meal with proteins seems to buffer cgm spikes, and snacking on proteins (cheese, nuts, minimally sweetened chocolate) seems key to preventing the hyper/hypo glycemic swings. the same for vegetables, though that is not controversial.
this is not an attempt to increase dietary protein per se, but a shift in diet away from carbs towards these two categories, which has had a net overall effect of increased protein intake. this aspect was not mentioned in your article, so i thought id point out: some part of health gains reported for high protein diets are from the reduction of glycemic intake and esp. these initial spiking events.
Chris
The share button for this post references a different post.
thank you. Got it corrected.
Not yet corrected on September 19, 2025
I suspect the protein leverage hypothesis may hold some truth, that protein needs vary by age. As for Huberman and Attia, I agree the former often promotes rubbish. Attia, on the other hand, has a mind sharper than any razor and is no slouch with data, and given your past interaction with him, I'm surprised you would simply dismiss him by saying he declined questions from the NY Times. So what? His views on this topic are not at all hard to find, along with his usual cogent and logical interpretation of the data linked to in his article (see below). As an older woman whose digestion is not what it once was, who fears getting the same sarcopenia that doomed her mother, I lift weights AND take a protein supplement on those days. It's actually quite hard for me to get even the measly RDA without a supplement.
https://peterattiamd.com/determining-optimal-protein-intake/
My question is how well have the mortality, atherosclerosis and Type2DM associations accounted for confounders such as LDL, obesity or body fat percentage, etc. It is, at least in theory, possible to eat a mostly plant-based diet, high in fiber and unsaturated fats and supplement with animal protein devoid of other nutrients. This could isolate the effects of higher caloric intake protein intake.
Also, what are your thoughts about this recent study:
https://cdnsciencepub.com/doi/10.1139/apnm-2023-0594?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200pubmed
you mentioned suggestions for breakfast, snacks and dinner - what about lunch!? Thank you!
I usually don’t eat lunch. Just a snack. Sometimes I’ll have sliced nonfat turkey on a slice of bread (cut in half) with some arugula and Dijon mustard
Thank you so much for taking the time to respond! And thank you for all the work you do bringing science to us. It’s refreshing and unbelievably important right now especially. Thanks again.
Dr. Topol, thank you for your Ground Truths article on protein intake. Question: is there a benefit to taking a supplement based on a collagen hydrolysate on joints? Is there clinical trial data supporting this?
Eric,
Thanks for giving attention to this issue. You’re right that protein dominates public discussion, and I share your skepticism of influencer-driven hype. I was an early fan of Huberman’s science-focused content, but agree he’s drifted from rigor. That said, broader interest in higher protein isn’t simply the product of influencer “brainwashing.”
From the lens of body composition—and especially sports performance—the case for higher protein is fairly strong. Consensus guidelines (ACSM, ISSN) recommend 1.2–2.0 g/kg/day for active individuals. In hypocaloric periods, higher intakes can aid lean mass retention, though with diminishing returns. The “1 g/lb” advice overshoots for most people: it’s not harmful with healthy kidneys, but rarely necessary outside of competitive or aesthetic goals. Two caveats: plant protein requires higher intake to achieve equivalent muscle protein synthesis (MPS), and older adults need more protein to trigger MPS due to anabolic resistance.
For an excellent review, see: https://www.strongerbyscience.com/protein-science/ The quoted 1.6 g/kg/day isn’t a hard ceiling but more of an inflection point; most people get ~90% of benefits there, but those pursuing maximal gains can justify going higher.
On safety, the balance of evidence shows high protein does not harm healthy kidneys. Recent studies even suggest mortality benefits of higher protein in CKD stages 1–3 (see recent large JAMA study and subsequent AJKD commentary calling for a more nuanced approach). At minimum, the science here is evolving—not closed.
As for CVD risk, here’s where I think we mostly agree: plant protein is clearly beneficial. Lean animal protein looks neutral, while processed and likely red meat drive risk. Mechanistic/animal studies on leucine are worth paying attention to, but shouldn’t be leveraged into broad anti-protein recommendations. The totality of evidence just doesn’t support that.